Gas turbine engines are utilized to power aircraft, including unmanned aerial vehicles (UAV). The gas turbine engines of UAVs typically include an exhaust system with one or more outlets that exhaust gases from the engines directly into the atmosphere. This arrangement can result in noise levels that may exceed government standards.
Attempts to provide an exhaust muffler on the UAV are often unsuccessful, particularly due to the compact and aerodynamic design of the UAV. These attempts can be further frustrated because exhaust mufflers should preferably attenuate not only noise from the turbine in the engine, but also noise from the combustion gases emanating from the engine. Exhaust mufflers that satisfactorily muffle the engine noise can cause external drag on the UAV or result in additional, undesireable weight.
Accordingly, it is desirable to have an exhaust muffler that satisfactorily attenuates engine noise as a result of turbine noise and combustion noise in a compact design. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.